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Ruby / Metaprogramming

Method_missing

Learn method_missing in Ruby through a focused explanation, a dedicated topic-specific example, an engineering boundary, and a mastery check.

12 min read • Advanced

method_missing is an atomic Ruby topic inside Metaprogramming. The example uses the named construct directly so you can see its syntax, data flow, and observable behavior.

Read the code by locating the exact feature named method_missing, then trace the value before and after that feature runs. This lesson is intentionally isolated from neighboring topics: changing identifiers alone would not reproduce the same behavior because the construct itself is different.

Topic-specific example

ruby-0060-55bb8ad0e7.rb
ruby Try It Live 
class Bag;def method_missing(name,*);return 42 if name==:answer;super;end;end;puts Bag.new.answer
Edge case / engineering note

For method_missing, test the boundary that makes the feature meaningful: invalid input, an empty value, a missing branch, lifecycle/cleanup, or a type/runtime constraint. Do not infer correctness only from the happy path.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

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